Worldwide pesticide usage and its impacts on ecosystem

A critical review of pesticides in aquatic environment: Current trends, environmental impacts, and advances in analytical extraction techniques

Pesticides are applied in agricultural fields to manage pests and diseases that threaten crop health and productivity. However, their presence in natural water systems is a significant concern due to their persistent composition and complex molecular structures. Additionally, their toxic and recalcitrant nature poses potential risks, leading to chronic health effects in humans. Typically detected in trace concentrations, pesticides present analytical challenges owing to their intricate chemical structures and diverse physical properties. Recent research highlights notable advancements in conventional pesticide extraction methods, aiming to develop eco-friendly and cost-effective techniques with high enrichment and recovery rates. This review begins by exploring the latest trends and ongoing research related to the occurrence and extraction of pesticides from various aquatic environments. The study then discusses the innovative extraction techniques currently employed for pesticide removal. Among liquid-phase microextraction (LPME) techniques, methods such as ionic liquid-based extraction (IL-LPME), deep eutectic solvent-based extraction (DES-LPME), air-assisted extraction, solidification of a floating organic drop (SFO), and ultrasound-assisted LPME are gaining attention due to their ease of handling, operational simplicity, cost-effectiveness, and environmental sustainability. In the, solid-phase extraction (SPE) field, researchers have increasingly utilized approaches like magnetic solid-phase extraction (MSPE), green sorbents, metal-organic framework (MOF) based extraction, cartridge-based SPE, and carbon nanotube-based SPE as the most widely adopted methods. These methods are preferred for their benefits, including efficient separation, rapid analysis, and environmentally sustainable practices. The latter sections of this review present a detailed comparative analysis of these extraction methods, evaluating critical parameters such as operational time, cost, chemical and energy consumption, and analytical accuracy.

Advanced performance and operational strategies of partitioned anaerobic membrane bioreactor combined with ferromagnetic biochar for pesticide wastewater treatment at low-temperature and insufficient hydraulic load

Accompanied by high energy consumption and the difficulty in maintaining process stability, the treatment of pesticide wastewater in cold climates remain a significant challenge due to its low biodegradability and complex composition. Therefore, this study developed a hybrid anaerobic membrane bioreactor (HAnMBR) that incorporates ferromagnetic biochar and a partitioned upflow anaerobic sludge blanket structure. Its performance was evaluated and compared to that of a conventional anaerobic membrane bioreactor (CAnMBR) under varying organic loading rate (OLR) and hydraulic loading rate (HLR) at 10 °C. Results indicated that the maximum average removal rates of COD, pyridine, and trichlorfon in HAnMBR were 17.3 %, 11.2 %, and 6.9 % higher than those in CAnMBR, respectively. The volatile fatty acid (VFA) concentration decreased by 14.8-55.4 %, and the electron transport system activity (ETSA) increased by 1.3-2.6 times. HAnMBR significantly reduced the sludge yield by 21.5-51.0 % and decreased the SVI by 13.3-39.4 %. The operational strategies were subsequently determined, including: an influent COD concentration of 8.0 g/L and a HLR of 0.9 m3/(m2·d); an OLR of 5 kg COD/(m3·d) and a HLR of 0.7 m3/(m2·d); and a HLR of 1.0 m3/(m2·d) and an OLR of 7 kg COD/(m3·d). This study offered a new process for effectively mitigating the impact of load shocks from high-strength wastewater at low temperatures, potentially expanding the application of AnMBRs.

Multidimensional effects of a glyphosate-based herbicide on Joannesia princeps Vell. (Euphorbiaceae): Morphoanatomical, metabolic, and genotoxic biomarkers as indicators of damage in a non-target native tree species

Glyphosate may negatively affect non-target tree species due to improper application management. We hypothesize that Joannesia princeps is sensitive to glyphosate and would show metabolic alterations and genome damage when exposed to this herbicide even at doses below those commonly applied in the field for weed control. We aimed: (i) evaluate the morphoanatomical, physiological, biochemical, and genotoxic responses induced by a glyphosate-based herbicide in J. princeps leaves; (ii) identify potential phytotoxicity biomarkers for biomonitoring environments exposed to herbicides. Three-month-old J. princeps seedlings were sprayed with a glyphosate-based herbicide at doses 0, 180, 360, 720, and 1440 g.ae.ha-1. These values correspond to 0 %, 12.5 %, 25 %, 50 %, and 100 % of the field doses applied in crops. After 12 days, we performed morphoanatomical, physiological, biochemical, and genotoxic analysis. Glyphosate exposure increased shikimic acid content in leaves, causing visible damage and structural changes. In treated plants, there was a reduction in CO2 assimilation, stomatal conductance, transpiration, and chlorophyll. The oxidative stress increased lipid peroxidation and increased superoxide dismutase and peroxidase activities. The glyphosate induced dose-dependent genotoxicity and cell death, mainly at higher doses. In conclusion, J. princeps is sensitive to the glyphosate-based herbicide, which causes multidimensional deleterious effects even in leaves without visual symptoms of phytotoxicity. Anatomical changes, shikimic acid, lipid peroxidation, and DNA damage are potential prognostic markers to assess glyphosate-induced damage in biomonitoring programs.

Insights into chlorination-induced degradation of sulfonylurea herbicides: Unraveling kinetics and intermediates during water treatment

Chlorination is a common method for drinking water disinfection due to its efficiency and low cost. The strong oxidative properties of chlorine can lead to reactions with dissolved organic compounds, resulting in various transformation products. This study investigates the chlorination-induced degradation of the sulfonylurea herbicides metsulfuron-methyl and chlorimuron-ethyl, which are frequently found in surface and groundwater. The degradation of these herbicides follows a second-order kinetic model. The apparent second-order rate constants for metsulfuron-methyl range from 3.2 to 244 M⁻¹ s⁻¹, while those for chlorimuron-ethyl range from 2.2 to 287.7 M⁻¹ s⁻¹ within a pH range of 4 to 9. Reaction with HClO effectively reduced the concentration of pesticides. Under acidic conditions, the reaction was significantly enhanced, likely due to hydrolysis or changes in the speciation of the organic compounds. In fact, the rate constant under acidic conditions was approximately 35 and 27 times higher than the reaction rate at more neutral pH for chlorimuron-ethyl and metsulfuron-methyl, respectively. The reaction rate with ClO⁻ approached zero for both herbicides, suggesting a minor or negligible pathway involving the hypochlorite anion. Mass spectrometry identified six chlorination products for metsulfuron-methyl and five for chlorimuron-ethyl. Although the specific reaction mechanisms were not fully elucidated, these products provided valuable insights into the fate of sulfonylureas under chlorination. Under typical disinfection conditions (pH 7 and 4 mg L⁻¹ chlorine), the half-lives of 17.8 minutes for metsulfuron-methyl and 26.6 minutes for chlorimuron-ethyl demonstrate the potential for effective degradation in relatively short timeframes. This study underscores the potential for effective removal of these herbicides in drinking water treatment and highlights the importance of evaluating degradation products over time, as they remain detectable even after seven days.

Legacy effects of four decades of insecticide applications on contemporary riverine benthic macroinvertebrates

Insecticides have known effects on riverine benthic macroinvertebrate (BMI) assemblages. However, there is limited understanding of the legacy effects of insecticides, particularly in watersheds that received decades of historical applications. From 1952 to 1993, over 6.2 million ha in the province of New Brunswick (Canada) was treated with one to twelve different insecticides including dichlorodiphenyltrichloroethane (DDT), aminocarb, fenitrothion, and phosphamidon. Using a contemporary BMI dataset that included 274 sites within watersheds that cover 50 % of New Brunswick, we evaluated the relative importance of historical insecticide applications and contemporary environmental variables in explaining variability in BMI assemblages. We found that historical insecticides explained a significant, but small, amount of variation in contemporary assemblages. The number of insecticide applications showed a stronger association with BMI metrics than the total amount of insecticide(s) applied, though contemporary environmental measures such as urban land use, substrate size, geology, and climate all had more explanatory power than insecticide metrics. Our results suggested that while contemporary environmental variables and historical insecticide applications both affect BMI assemblage composition, the former often had a stronger role in structuring assemblages. Recognizing the influence of legacy stressors provides important context for understanding contemporary bioindicator responses to environmental change.

Gas-liquid chromatography as a tool to determine vapor pressure of low-volatility pesticides: A critical study

BACKGROUND

The vapor pressure of pesticides at room temperature is one of the fundamental properties for predicting their volatilities and the likelihood of their movement into the environment. It is also highly valuable for decision making in agriculture and agro-industries. Direct methods applicable to low-volatile substances include gas saturation and molecular effusion techniques; however, they have several drawbacks. We propose an indirect method based on gas-liquid chromatography using short capillary columns coated with stationary phases with high phase ratio and operated at very high flow rates.

RESULTS

The method was applied to determine the vapor pressure of twenty pesticides, ranging from intermediate to very low volatilities (<0.133 mPa). Chromatographic assumptions were critically and comprehensively discussed, and the precision and accuracy of the method were evaluated using three fatty acid methyl esters (referred as validation solutes) with known and reliable vapor pressures available over a wide range of temperatures. The relative standard deviations of the primary data were below 4 % and increased to 18 % for extrapolated vapor pressures. The measurement conditions allowed for the extension of retention measurements to relatively lower temperatures while ensuring reasonable operational times, thereby, minimizing the extent of temperature extrapolation required. The target pesticides included widely used chemical compounds with multiple functional groups and molecules exhibiting configurational isomerism, whose individual vapor pressure could be distinguished provided that sufficient chromatographic selectivity was achieved.

SIGNIFICANCE

This work provides a readily useable technique which employs instruments commonly found in both academic and industrial laboratories. Furthermore, the method is simple, robust, and reliable, allowing to estimate the vapor pressures of low-volatile and semi-volatile pesticides within reasonable analysis time and overcoming the main limitations associated with traditional methods.

Effect of methoxychlor on liver function, lipid peroxidation, and antioxidants in experimental rats

Background

Methoxychlor (MXC), a widely used pesticide, poses significant toxicological risks to various biological systems. It is an environmental contaminant and the only organochlorine pesticide still using instead of DDT. Endocrine disruption of MXC is also under investigation.This study aimed to investigate the effects of MXC on antioxidant status, lipid peroxidation, and liver metabolism in experimental rats.

Methods

Male Wistar rats were divided into control and treatment groups, with the latter receiving 150 mg/kg and 250 mg/kg body weight (BW) of MXC via oral administration for 30 days. Liver function was assessed by measuring circulating biomarkers, including Alanine Transaminase (ALT), Aspartate Transaminase (AST), and Alkaline Phosphatase (ALP). Oxidative damage was evaluated by determining Thiobarbituric Acid Reactive Substances (TBARS), hydroperoxide (HYP), and other lipid peroxidation markers. Key enzymes involved in antioxidant defense mechanisms were also analyzed in the liver of experimental animals.

Results

Our results demonstrated a significant increase in ALT, AST, and ALP levels in the serum of rats exposed to MXC, indicating impaired liver function. This was accompanied by elevated lipid peroxidation, further emphasizing oxidative stress. Moreover, the activities of antioxidant enzymes such as SOD, GPx, and CAT were markedly reduced in the MXC-exposed groups compared to the controls, suggesting a compromised antioxidant defense system.

Conclusion

These findings suggest that methoxychlor exposure disrupts liver function and induces oxidative stress by enhancing lipid peroxidation, thereby depleting natural antioxidant defenses. This study highlights the potential hepatotoxic effects of methoxychlor and underscores the role of oxidative stress in mediating its toxicity.

Distribution and accumulation dynamics of fungicide azoxystrobin in the soil-plant system

Azoxystrobin is a widely used fungicide belonging to the strobilurin group, primarily employed to control a range of fungal diseases in crops, including pepper (Capsicum annuum L.). As a systemic pesticide, it effectively inhibits mitochondrial respiration in fungi, thereby preventing their growth and spread. However, concerns have emerged regarding its environmental persistence and potential bioaccumulation in soil-plant systems. This study conducted a field study and utilized HPLC-MS/MS for sample analysis, investigating the distribution and accumulation dynamics of azoxystrobin in the soil-plant system, with a focus on its behavior in different soil depths and plant tissues. The results show that pesticide concentration in the shoots remained consistently low throughout the observation period. In contrast, the concentration in roots gradually increased over time, with a peak observed in the top soil around the 10th day (16.56 mg/kg), followed by a rapid decrease to 1.44 mg/kg by the 14th day after application. The pesticide concentration in the subsurface soil remained relatively stable, reaching 0.91 mg/kg by the 35th day. The percentage distribution of pesticides in different parts of the system was as follows: top soil > subsurface soil > roots > shoots. The biological concentration factor (BCF) was greater than 1 during the early and middle-late growth stages, and both the biological accumulation coefficient (BAC) and translocation factor (TF) remained consistently below 1. This study highlights the role of the top soil as a primary pesticide reservoir and suggests limited translocation efficiency from roots to shoots. This pattern of accumulation could have significant implications for environmental health by indicating potential risks of pesticide persistence in the soil, emphasizing the need for further research on optimizing agricultural practices to mitigate pesticide accumulation in the environment.

A review on enzymatic colorimetric assays for organophosphate and carbamate pesticides detection in water environments

To monitor pesticides, which have grown to be a significant environmental and public health concern, sensitive, selective, and economical analytical tools must be developed. With advantages including high sensitivity, quick processing, and the potential for on-site monitoring, enzymatic colourimetric assays have surfaced as a potential substitute for conventional pesticide detection, particularly for organophosphate (OPPs) and carbamate pesticide detection. The toxicological effects of pesticides on humans and the environment are examined first in this review, followed by examining the concepts and mechanisms behind enzyme activity and colourimetric methods. Besides, single and double-enzyme-mediated colourimetric techniques are also studied to detect OPPs and carbamate pesticides. Furthermore, colourimetric smartphone platforms and paper-based devices have both garnered a lot of attention. These advanced approaches offer many pesticide detection options, from high-sensitivity lab-based procedures to on-site and in-field technologies. The fourth section of this review employs newly published studies to explore the applicability of these approaches for onsite OPPs and carbamate pesticide detection. Lastly, the challenges associated with enzymatic colourimetric assays, such as matrix effects and enzyme stability, and prospects for current and future research are discussed.

Comparative transcriptomics reveals different profiles between diflubenzuron-resistant and -susceptible phenotypes of the mosquito Culex pipiens

BACKGROUND

Chitin-synthesis inhibitors (CSIs) represent a major tool in vector control. The intensive use of these compounds has led to the evolution of resistance against several CSIs, including diflubenzuron (DFB). DFB resistance has been associated to a target-site mechanism; however, studies investigating the gene expression profile of resistant phenotypes are limited, preventing a full understanding of DFB resistance. Here, we analyzed the constitutive gene expression of susceptible and DFB-resistant individuals of the mosquito Culex pipiens, a major disease vector in temperate areas.

RESULTS

Comparative gene expression analysis between susceptible and DFB-resistant individuals identified 527 differentially expressed genes (i.e., 432 up-regulated and 95 down-regulated genes). Among the up-regulated genes, 87 genes belong to gene families associated with insecticide resistance in arthropods, such as cytochrome P450s, glutathione-S-transferases, UDP-glucuronosyltransferases, heat shock proteins and cuticular proteins (CPs). Interestingly, the CP transcripts were the most abundant among up-regulated genes (73 of 87), and furthermore they constitute 11 of the 20 most over expressed genes. The enrichment of transcripts associated with cuticle synthesis was also identified by the Gene Ontology (GO) enrichment analysis.

CONCLUSIONS

Adaptation to insecticides can involve transcriptional changes in genes encoding for multiple defense mechanisms. Our results identified the over-expression of transcripts associated with detoxification and cuticle synthesis in DFB-resistant individuals of Cx. pipiens. Multiple mechanisms, beyond the known target-site mechanism, may therefore contribute to the DFB-resistant phenotype. Together these findings corroborate the complexity underpinning the resistant phenotypes and provide important information for the implementation of effective control strategies against mosquito vectors. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Unveiling the photodegradation of tralkoxydim herbicide and its formulation in natural waters: Structural elucidation of transformation products and toxicity assessment

Pesticide degradation products (DPs), as emerging contaminants, are being detected in aquatic environments due to the widespread use of their active substances and pose potential risks to aquatic ecology and human health. However, their identification is challenging due to the many environmental conditions that influence their degradation processes. The photodegradation of the herbicide tralkoxydim and its formulation has been studied in ultrapure, spring and river waters and has shown rapid degradation. The photodegradation of tralkoxydim was slower in natural water and in the presence of humic acids (HA) than in ultrapure water, with half-lives of 5.1 h for river water and 1.1 h for ultrapure water. For the first time, three degradation products were identified in aquatic media using HPLC-TOF-MS/MS. These include photoisomerization, photolysis of the N-O bond of the oxime resulting in the tralkoxydim imine (major DP), and cyclization leading to tralkoxydim oxazole. Quantitative structure-activity relationship (QSAR) models were employed to approximate the potential ecotoxicological and environmental impacts of tralkoxydim and its DPs. Additionally, the toxicity of the isolated DPs was evaluated using a standard microtest bioassay with Vibrio fischeri bacteria. The results show that tralkoxydim imine and tralkoxydim oxazole exhibit high toxicity.

Effects of pesticide application on soil bacteria community structure in a cabbage-based agroecosystem in Ghana

Modern sustainable agriculture often relies on pesticide application, which may unintentionally affect non-target soil microorganisms. This study assessed the effects of commonly used pesticides in cabbage cultivation on bacteria diversity, composition, and abundance in soils from some farming communities in Bosome Freho District, Ghana. The pesticides included a neonicotinoid (acetamiprid), microbial agents (Pieris rapae granulosis virus+ Bacillus thuringiensis), avermectin (emamectin benzoate), and pyrrole (chlorfenapyr). Soil samples were collected from non-contaminated (NCS), abandoned pesticide-contaminated (AB-PCS) and actively pesticide-contaminated (AC-PCS) soils. Bacteria communities were analysed in the soil at phylum, class, order, family, genus, and species levels using 16S rRNA gene sequencing. The soils were also analyzed for physicochemical properties. Our results showed a decrease in bacteria diversity and abundance in pesticide-contaminated soils in the following order: NCS > AB-PCS > AC-PCS. Sorensen's coefficient of similarity indicated major shifts in bacteria taxa composition due to pesticide contamination. In NCS, Pseudomonas veronii, Bacillus sp., and Prevotella albensis were the most abundant species, while Rhodoplanes elegans and Nostocoida limicola dominated AB-PCS. In AC-PCS, R. elegans, Gemmata obscuriglobus, Nitrospira calida, and N. limicola were the most abundant species. The abundance of Bacillus sp., P. veronii, and P. albensis decreased in the contaminated soils, while the abundance of N. calida, Cystobacter sp., Pedomicrobium australicum and Byssovorax cruenta was higher in the contaminated soils. Key genera involved in nutrient cycling such as Clostridium, Bacillus, Prevotella, Pseudomonas, and Arthrobacter, declined in abundance in pesticide exposed soils. In contrast, an increase in abundance of various taxa such as Pedomicrobium, Hyphomicrobiaceae, Pirellulaceae, Comamonadaceae, Nitrospirales, Nitrospira, Anaerolineae, Planctomycetes, Acidobacteriaí and Nitrospirae was observed in the contaminated soils. These bacteria may possess bioremediation potential that could be exploited for environmental remediation. Soil physicochemical properties and nutrient levels varied across the three soil treatments, with potential implications for bacteria community structure.

Occurrence and environmental risk assessment of pesticides reveal important threats to aquatic organisms in precordilleran rivers of north-central Chile

While pesticides are essential for food production, their widespread use poses environmental risks beyond lowland areas. Recent evidence indicates that mountain ecosystems are also vulnerable due to both local agriculture and long-range atmospheric transport. This study assesses pesticide contamination and ecological risks in five mountainous agricultural watersheds of north-central Chile, where pesticides support intensive crop production. Using primarily polar organic chemical integrative samplers (POCIS), complemented by sediment samples, we found pesticides at 26 of 30 sampled sites. Detection varied by location and method. Desethylatrazine, an atrazine metabolite, was most frequently found in POCIS samples, detected at 20 sites across all watersheds. While other pesticides only occurred at few sites, their presence across multiple, geographically dispersed locations contributed to extensive ecological risk. Northern watersheds (Limarí, Choapa, Aconcagua) showed the highest ecological risks, despite lower pesticide loads, due to the presence of highly toxic insecticides. Key factors influencing pesticide distribution included water conductivity, agricultural land use, and latitude. Ecotoxicological risk assessments revealed eight pesticides exceeding high-risk thresholds for aquatic organisms-mainly insecticides and fungicides. Pyrethroids such as deltamethrin, cyfluthrin, and lambda-cyhalothrin posed severe threats to fish and invertebrates. High-risk levels were also detected in sediments, particularly in the northernmost Limarí watershed. These findings underscore the urgent need for targeted monitoring and stricter pesticide regulation in mountain freshwater ecosystems of Chile, which are vital water sources and harbor unique biodiversity. This study provides one of the first comprehensive evaluations of pesticide risks in mountainous rivers, highlighting the ecological threats from agricultural contaminants.

Synthesis of Neem-Oil-Infused Niosome and Starch Nanoparticle Coatings for Preserving the Quality of Strawberry Fruit

Strawberries face marketing challenges due to their short post-harvest shelf-life, largely impacted by shrivelling, weight loss, fungal decay, and mechanical damage. Neem oil (NO) is known for its shelf-life extension benefits; however, encapsulation is needed to maintain its efficacy. This study aimed to stabilize and encapsulate NO in a polymeric and lipid material to preserve the quality of strawberries stored at 4 ± 1 °C, 80 ± 2% RH for seven days. After seven days, the nanoparticle-coated fruits showed a weight loss of around 5.9% with niosomes and 8.9% with starch nanoparticles, while the control had a significant 32.45% weight loss. Additionally, both nanoparticle coatings significantly (p < 0.05) preserved fruit colour compared to the untreated control. The findings suggest that nanoparticle coatings could serve as an active agent in preserving the quality of strawberries within the food supply chain. The study provides valuable insights into post-harvest management and fruit preservation, showcasing the effectiveness of these coatings as active packaging solutions.

Distribution of dialkylphosphate metabolites and 1- hydroxypyrene in parent-toddler pairs from agricultural communities and their impacts on toddler's developmental performance

The widespread presence of pesticides and polycyclic aromatic hydrocarbons (PAHs) in agricultural settings raises significant concerns about early-life exposure and its potential impact on toddler health and development. This cross-sectional study evaluated exposure to organophosphate and PAH metabolites among 154 parent-toddler pairs in northern Thailand, focusing on developmental outcomes. Urinary levels of dialkylphosphate (DAP) metabolites and 1-hydroxypyrene (1-OHP) were measured. Results showed that toddlers had significantly higher geometric mean levels of total DAP metabolites with a geometric mean of 24.38 µg/g creatinine compared to 17.25 µg/g creatinine in parents. A significant positive correlation was observed between the urinary levels of total dimethylphosphate (total DMP) and 1-OHP in both parents and toddlers (r = 0.290 for total DMP, r = 0.485 for 1-OHP), indicating shared environmental exposures. Proximity to farmland was a significant factor, with shorter distances associated with higher urinary total DMP and total DAP levels in toddlers (Beta = -19.8, 95 %CI = -37.3, -2.3 for total DMP, and Beta = -27.5, 95 % CI = -47.7, -7.4 for total DAP). Toddlers' behavior, such as playing on farmland, was linked to significantly elevated urinary 1-OHP levels (Beta = 121.5, 95 % CI = 8.5, 234.5). Notably, an inverse association was found between DMP levels and receptive communication scores (Beta = -0.009, 95 % CI = -0.018, -0.001), suggesting potential adverse effects on neurodevelopment. These findings underscore the vulnerability of toddlers in agricultural communities to environmental contaminants and emphasize the need for targeted interventions to reduce exposure risks and promote safer agricultural practices. The study provides crucial insights for future research and policy development in environmental health.

Impact of pesticides on soil health: identification of key soil microbial indicators for ecotoxicological assessment strategies through meta-analysis

Pesticides remain a cornerstone of modern agriculture. Despite their key role, it is well documented that pesticides can have considerable off-target effects on a range of organisms. The effects of pesticides on soil health, and more importantly on soil microbiota, are currently not well addressed at the regulatory level, despite cumulative evidence for the pivotal role of the soil microbiota on ecosystem functioning. Here, we use a meta-analysis to assess the effects of pesticides on soil health parameters identifying key biological indicators for environmental risk assessment analysis. We demonstrate that ammonia oxidizing archaeal and bacterial amoA gene abundance were the most consistent indicators for pesticide exposure, with inhibition driven by herbicides and fungicides. Our meta-analysis, combined with their key functional role and the existence of well-standardized, high-resolution methods for monitoring their abundance, highlighted the potential of ammonia-oxidizing microorganisms (AOMs) as indicators of the toxicity of pesticides on soil microbiota. AOM could serve as drivers of chemical innovation in a "benign and sustainable by design" approach where new pesticide compounds will have to meet sustainability targets and ensure soil health preservation.

Spatial distribution, phase partitioning, and ecological risk assessment of typical pesticides in Yangtze River Basin

Yangtze River Basin (YRB) is the largest agricultural and economic corridor in Asia, accounting for 40 % of China's rice production and 49 % of its arable land. Additionally, the Huangpu River (HR), the largest river in Shanghai, features developed agriculture and an extensive shipping industry. Overall, extensive agricultural activities coupled with frequent pesticide applications have resulted in aquatic contamination. This study investigated the spatial distribution and partitioning trends of 57 common pesticides, and assessed their ecological and human health risks in 30 river sections of YRB. We found that the total concentration of pesticides (∑57 pesticides) in the dissolved phase, suspended particulate matter (SPM) phase, and surface sediment ranged 601.82 -2415.91 ng/L, 65.04 -1863.28 ng/L, and 68.54 -424.84 ng/g dry weight, respectively. Organochlorines and pyrethroids were predominant in the SPM phase, while triazines and neonicotinoids were predominant in the dissolved phase. The sources of dichlorodiphenyltrichloroethane (DDT) substances could be attributed to historical residues and vessels' antifouling systems. Most pesticides had strong migration ability and were not readily deposited in sediment. Moreover, sediment was also potential secondary pollution sources of triazines. Organochlorines, pyrethroids, and neonicotinoids posed significant ecological risks, despite its low concentration, traditional organochlorine still poses a certain ecological threat. Children were more susceptible than adults to noncarcinogenic and carcinogenic risks from unintentional oral exposure. Stringent management of pesticides is imperative with ongoing monitoring.

Nano-interface enhanced electrochemical sensing of hazardous organochlorine pesticides and prospects with ZnO based nanomaterials

Detection and analysis of organochlorine pesticides (OCP) residue is getting significant research importance because of their extensive use despite their hazardous effects on the health of people and the ecosystem. Despite the implementation of regulations and bans to safeguard human health and the environment, reports frequently reveal the continued use of these harmful chemicals in quantities exceeding the recommended limits set by regulatory boards. Data on the use of OCP from India, the most populous country, and African countries is not very encouraging. Conventional methods used for pesticide identification rely on high-cost and bulky instruments, which are also time-consuming and resource-intensive. Therefore, a low-cost, simple, easy-to-handle, and portable pesticide detection device is the need of the hour to enhance the convenience of routine detection and analysis. Nanomaterial-based sensors, composed of metal oxides, polymers, metals, enzyme-functionalized nanostructures, and nanocomposites, hold significant potential for monitoring pesticides, even at extremely low levels, and offer a unique alternative to traditional detection methods. This study examines the potential health risks associated with OCP residues and commonly used analytical techniques for pesticide detection. It also thoroughly examines the latest developments in nanomaterial-based electrochemical sensors, specifically focusing on ZnO-based nanomaterials for OCP detection. Researchers have successfully experimented with ZnO nanomaterials for pesticide degradation, in addition to their use in detection. This review provides a summary of the detection limits, linear ranges, and various fabrication methods of these developed sensors. It also addresses the practicality issues and detection strategies, thereby providing a comprehensive overview of the state of the art in OCP detection using nanomaterials. Furthermore, this review provides insights on potential future perspectives in the area from the authors' standpoint.

Comparison of salting-out assisted liquid-liquid extraction to polymeric solid phase extraction for liquid chromatography tandem mass spectrometry of neonicotinoids insecticides and metabolites in wastewater: Occurrence and aquatic risk assessment

Neonicotinoids are among the most widely used insecticides worldwide. Many studies have revealed that this class of pesticides, used both in agricultural crops and for insect control in cities, can be metabolized to a variety of different compounds with varying effects in the environment and to human health. Considering the widespread use of neonicotinoids and likely occurrence of metabolites, new methodologies that evaluate the presence of these compounds in water and wastewater are crucial to better understand occurrence, exposure and to develop exposure control strategies. This study compares trace-level analysis of 7 neonicotinoids and 11 neonicotinoid metabolites in municipal wastewater samples, using polymeric solid phase extraction (SPE) and salting-out assisted liquid-liquid extraction (SALLE) sample preparation methodologies for liquid chromatography tandem mass spectrometry, with a new enhanced efficiency Uni-Spray™ ion source. Extraction comparison showed advantages of both methods and demonstrated good recovery to quantify the analytes at very low levels. Method detection limits of the SALLE method ranged from 0.0031 to 0.086 μg L-1. Nine effluent and nine influent samples, collected from wastewater treatment plants from 7 cities across Nebraska, were extracted by the SALLE method and analyzed by LC-MS/MS. Results showed that six compounds were not detected in these samples (clothianidin-desmethyl, thiacloprid, thiacloprid-amide, imidacloprid-olefin, thiamethoxam-urea and 5-hydroxy-imidacloprid), and the highest average measured concentrations were observed for clothianidin-urea, clothianidin, and dinotefuran (0.29, 0.11, and 0.088 μg L-1, respectively). In silico predictions of preliminary aquatic-life risk assessment demonstrated that no compound occurred above environmental risk concentrations. There are no wastewater discharge limits established for the contaminants evaluated, however, the measured wastewater concentrations for imidacloprid and clothianidin exceed limits established by U.S. EPA and RIVM for freshwater. The method demonstrates great potential as an occurrence and exposure monitoring method for neonicotinoids and their metabolites in wastewater.

Cellular and individual toxicity of diflubenzuron for the chronic exposure in Daphnia magna: focus on oxidative stress, chitin content, and reproductive outcomes

Diflubenzuron (DFB) is important to study due to its widespread use in agriculture and vector control. These harmful chemicals can persist at trace concentrations in aquatic systems for extended periods, potentially exerting adverse effects on aquatic life. This research investigated the toxic effects of DFB on the water flea (Daphnia magna) at environmental concentrations during a chronic exposure period of 21-days. D. magna is a key indicator species in freshwater ecosystems and plays a vital role in the aquatic food web. The EC₅₀ value was found to be 51.76 ng L-1, with a 95% confidence interval (CI) of 45.65-58.70 ng L-1. The survival rate of D. magna was 12.5% at a DFB concentration of 10 ng L-1 during the chronic exposure period, which was significantly lower than that of the other groups (p < 0.05). Moreover, the increased DFB concentration significantly reduced the fecundity of D. magna. In detail, the total of reproduction was significantly decreased according to increasing DFB concentration, while an increase in undeveloped embryos and male offspring was increased (p < 0.05). Ultimately, the number of normal offspring capable of reproduction decreased, and the growth of organisms showed a concentration-dependent decline. Exposure to DFB induced a notable increase in the antioxidant enzymes superoxide dismutase and catalase, as well as lipid peroxidation in daphnids, suggesting an activation of the antioxidant system and cellular damage in organisms. Furthermore, chitin content increased in response to DFB exposure, suggesting a potential compensatory mechanism to strengthen the exoskeleton. These findings underscore the adverse effects of DFB on D. magna reproduction, growth, and overall physiological health, even at environmentally relevant concentrations. This research indicates the necessity of investigating the ecotoxicological risk of DFB contamination in aquatic ecosystems.

Next-generation nanotechnology-integrated biosurfactants: Innovations in biopesticide development for sustainable and modern agriculture

The increasing global demand for eco-friendly agricultural practices necessitates the development of innovative pest management solutions, effectively addressing the environmental and ecological issues associated with traditional chemical pesticides, such as pest resistance, environmental contamination, and non-target organism toxicity. Biosurfactants, biologically derived amphiphilic molecules from microbial and plant sources, offer distinct advantages including biodegradability, excellent surface-active properties, and inherent antimicrobial efficacy, making them as promising candidates for sustainable pest management and control. Concurrently, nanotechnology introduces innovative delivery mechanisms, enhancing biopesticide stability, solubility, and targeted application, significantly minimizing off-target impact and environmental footprint. This review emphasizes recent breakthroughs in integrating biosurfactants with nanotechnological strategies to produce advanced biopesticides. Key advancements include the role of biosurfactants to increase the bioavailability and effectiveness of active ingredients and utilizing nanopesticides for targeted pest control with improved precision. Combining the unique amphiphilic properties of biosurfactants and the precise targeting capabilities of nanocarriers presents substantial improvements in pest management efficacy and aligns closely with Integrated Pest Management (IPM) principles. Despite these promising developments, significant knowledge gaps remain, including understanding the interactions between biosurfactants, nanomaterials, and the environmental matrices, as well as assessing long-term ecological impacts and safety profiles associated with nanopesticide usage. This article outlines critical research areas requiring further exploration to optimize biosurfactant-nanotechnology systems for large-scale agricultural deployment. Addressing these challenges will facilitate broader adoption, ensuring sustainable pest control practices that significantly contribute to global food security and environmental preservation. Integrating biosurfactants with nanotechnology represents a transformative approach in agricultural pest management, offering substantial potential to revolutionize sustainable agriculture through effective, environment-friendly solutions.

Biochemical basis of resistance toward maize insect pests of different feeding guild and their inter-guild interactions

MAIN CONCLUSION

Biochemical compounds and signaling molecules act as direct and indirect defenses against maize pests of different guilds and crucial for natural enemies' interactions. Maize (Zea mays L.) is an important multipurpose cereal crop that contributes to global feed and food demands and is persistently under the attack of several pests of different feeding guilds. However, concerns over the drawbacks of extensive pesticide use in natural ecosystems, including health hazards and the need for cost-effective pest control strategies, are growing. Wide opportunities are available to harness native plant resistance and natural enemies for insect pest management. In this context, it is critical to understand the biochemical basis of maize genotype resistance to insects from various feeding guilds as well as their inter-guild interactions. The critical role of various herbivore-induced plant volatiles (HIPVs) in mediating tritrophic interactions between maize plants, insect pests, and their natural enemies should be considered when developing strategies for pest management. This review synthesizes the important maize defense systems against different feeding guild pests, shedding light on recent progress and insights into the long-recognized maize defense compounds. In addition to the tritrophic interactions facilitated by HIPVs in the maize ecosystem, there has also been a focus on examining the impacts of inter-guild interactions resulting from damage caused by pests from varying feeding guilds on indirect defense systems mediated by maize plants.

Bioluminescent imaging of an oomycete pathogen empowers chemical selections and rational fungicide applications

Fungicides play an indispensable role in ensuring food security. However, rational chemical selection and fungicide precision application guidance remain constrained by the limitations in real-time monitoring of tracking pathogens within plant tissues. In the current study, we generated a genetically stable Phytophthora infestans strain (PiLuc) expressing luciferase gene, which serves as a dual-mode quantification platform for both in vitro and in vivo throughput screening. Consequently, we designed a 96-well plate high-throughput screening system to assess compounds inhibitory efficacy using PiLuc. Crucially, bioluminescence imaging enabled visualization of PiLuc in potato leaves and tubers during early infection stage, which is invisible to the naked eye. Capitalizing on the semi non-destructive and visual advantages, we developed a system for fungicide bioavailability evaluation and dosage-response assessment in tuber tissues, integrating real-time dynamic monitoring of pathogen. The development of bioluminescent imaging of late blight pathogen establishes an enabling platform for high-throughput fungicide screening while improving the precision bioavailability assessments.

Pesticides application rate maps in the European Union at a 250 m spatial resolution

Our work targets mapping of pesticides application rates within the European Union at a 250 m spatial resolution. Source data include global estimates of pesticide inputs, high resolution crop maps and pesticide usage reported by EUROSTAT official figures. Previously published global pesticide application rates in PEST-CHEMGRIDS are used as first guess estimates. These are then adjusted using a calibration dataset gathered from pesticide use in agriculture. The estimation of the applied mass by country and crop type is then combined with high resolution crop maps. The procedure explicitly accounts for data quality and uncertainty through a Maximum Likelihood estimation procedure. This data product features detailed spatial distributions of pesticide inputs, facilitating evaluation of pesticide fate and transport, biogeochemical transformations as well as environmental risk assessment.

Effects of herbicide mixtures on the diversity and composition of microbial community and nitrogen cycling function on agricultural soil: A field experiment in Northeast China

Herbicide mixtures application is a widespread and effective practice in modern agriculture; however, a knowledge gap exists regarding the potential ecotoxicological effects of herbicide mixtures in agricultural systems. Here, the effects of various doses of herbicide mixtures (atrazine, nicosulfuron, and mesotrione) under different varieties of maize cultivation on the structure and function of microbial communities and soil chemical parameters were clarified through field experiments. The results showed that the application of herbicide mixtures increased the bacterial and fungal community alpha diversity at jointing and maturity, indicating a prolonged effect of the herbicide mixtures. Moreover, herbicide mixtures alter the composition of bacterial and fungal communities, with sensitive taxa suppressed and herbicide-tolerant taxa enriched. The herbicide mixtures significantly reduced the abundances of Bacillus even at lower doses, but Penicillum was enriched. FAPROTAX analysis and quantitative PCR (qPCR) results showed that herbicide mixtures inhibited the soil nitrogen-cycle process and related genes AOA-amoA, AOB-amoA, and nifH at maize seedling stage. Moreover, network analysis showed that low concentrations of the herbicide mixtures increased bacterial interactions while high concentrations inhibited them, which indicated that the network complexity may be herbicide concentration dependent. A synthetic community (SynCom) consisting of six bacterial strains was established for the biodegradation of the herbicide mixtures based on the analysis of the bacterial network, which resulted in an increase in the degradation efficiency of nicosulfuron by 15.90%. Moreover, potted maize experiment showed that the addition of the SynCom alleviated the toxic effects of herbicide mixtures on the plants. In summary, this study provides a comprehensive perspective for assessing the ecological risk at taxonomic and functional levels and the biodegradation approach of herbicide mixtures residue on agricultural soils in Northeastern China.

Dose-dependent effects of chlorpyrifos on liver injury, intestinal dysbiosis, and metabolic perturbations in C57BL/6J mice

The organophosphorus pesticide chlorpyrifos (CPF) is widely utilized in agriculture to protect crops from pests and diseases. Concerns regarding its extensive use have emerged due to the substance's persistence, bioaccumulation, endocrine disruption, and associated toxicity, which may lead to various adverse reactions. In this study, 32 male C57BL/6 J mice were orally administered varying doses of CPF over a period of two weeks. Metabolic perturbations resulting from subacute exposure to CPF were assessed using LC-MS/MS-based untargeted metabolomics, alongside biochemical analysis and histopathological techniques. The 16S rRNA gene sequencing method was employed to evaluate changes in the gut microbial community within the cecal contents of mice exposed to CPF. In vivo studies have shown that CPF exposure induced dose-dependent damage and dysregulation of the intestinal microbiota in mouse colonic tissues. This was characterized by significant alterations in the gut microbiota, increased intestinal permeability and elevated levels of lipopolysaccharides. These changes may have compromised intestinal barrier function and facilitated the transfer of intestinal microbial metabolites and endotoxins to the liver, subsequently leading to liver injury. Collectively, this study elucidates a potential mechanism by which CPF triggers liver injury through alterations in the intestinal microbial community and increased intestinal permeability. These findings not only enhance our understanding of the toxicological effects of CPF but also contribute to the assessment of health risks associated with CPF exposure.

Sublethal glyphosate exposure reduces honey bee foraging and alters the balance of biogenic amines in the brain

Glyphosate is a broad-spectrum herbicide that inhibits the shikimate pathway, which honey bees (Apis mellifera), a non-target beneficial pollinator, do not endogenously express. Nonetheless, sublethal glyphosate exposure in honey bees has been correlated to impairments in gustation, learning, memory and navigation. While these impacted physiologies underpin honey bee foraging and recruitment, the effects of sublethal glyphosate exposure on these important behaviors remain unclear, and any proximate mechanism of action in the honey bee is poorly understood. We trained cohorts of honey bees from the same hives to forage at one of two artificial feeders offering 1 mol l-1 sucrose solution, either unaltered (N=40) or containing glyphosate at 5 mg acid equivalent (a.e.) l-1 (N=46). We then compared key foraging behaviors and, on a smaller subset of bees, recruitment behaviors. Next, we quantified protein levels of octopamine, tyramine and dopamine, and levels of the amino acid precursor tyrosine in the brains of experimental bees collected 3 days after the exposure. We found that glyphosate treatment bees reduced their foraging by 13.4% (P=0.022), and the brain content of tyramine was modulated by a crossover interaction between glyphosate treatment and the number of feeder visits (P=0.004). Levels of octopamine were significantly correlated with its precursors tyramine (P=0.011) and tyrosine (P=0.018) in glyphosate treatment bees, but not in control bees. Our findings emphasize the critical need to investigate impacts of the world's most-applied herbicide and to elucidate its non-target mechanism of action in insects to create better-informed pollinator protection strategies.

A network toxicology and molecular docking-based approach revealed shared hepatotoxic mechanisms and targets between the herbicide 2,4-D and its metabolite 2,4-DCP

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and its major environmental metabolite 2,4-dichlorophenol (2,4-DCP) are pollutants associated with hepatotoxicity, whose molecular mechanisms remain poorly understood. This study investigated the molecular pathways and targets involved in 2,4-D and 2,4-DCP-induced hepatotoxicity using protein-protein interaction (PPI) network analyses and molecular docking. Target genes were identified using PharmMapper and SwissTargetPrediction, and cross-referenced with hepatotoxicity-related genes from GeneCards and OMIM databases. The PPI network, constructed via STRING and visualized in Cytoscape, revealed 12 critical hub nodes, including HSP90AA1, RXRA, EGFR, SRC, CREBBP, PIK3R1, ESR1, AKT1, RAF1, IGF1R, MDM2, and MAPK14. Gene Ontology (GO) analysis indicated processes such as apoptosis, oxidative stress, mitochondrial dysfunction, and lipid metabolism impairment, while Reactome pathway analysis highlighted disruptions in PI3K/AKT and nuclear receptors signaling. Molecular docking confirmed significant interactions of 2,4-D and 2,4-DCP with key proteins, including SRC, AKT, RXRA, MDM2, and HSP90AA1. These results suggest that 2,4-D and 2,4-DCP share similar toxic mechanisms, providing new insights into their hepatotoxicity pathways for the first time.

Growth-promoting effects of arbuscular mycorrhizal fungus Funneliformis mosseae in rice, sesame, sorghum, Egyptian pea and Mexican hat plant

Excessive use and overreliance on chemical fertilizers threatens soil health and environmental sustainability, necessitating eco-friendly alternatives like arbuscular mycorrhizal fungi (AMF). The benefits of AMF are well-documented in staple crops, their effects on diverse species-particularly legumes and non-crop models under uniform conditions-remain underexplored, limiting their scalable adoption. This study evaluated Funneliformis mosseae's role in enhancing growth, nutrient uptake, and stress resilience across five species: rice (Oryza sativa), sesame (Sesamum indicum), sorghum (Sorghum bicolor), Egyptian pea (Sesbania sesban), and the non-crop Kalanchoe daigremontiana. The pot-experiment was conducted in natural open-field conditions (e.g., ambient light, temperature, and humidity) and inoculated plants were analyzed for biomass yield, nutrient concentrations, and physiological parameters to evaluate F. mosseae's efficacy as a sustainable growth promoter. Inoculation with F. mosseae significantly enhanced plant performance across all species. Rice exhibited a 43% increase in dry biomass, alongside 53% higher phosphorus uptake and 24.5% greater magnesium accumulation. Root development improved markedly, with sesame, sorghum, Egyptian pea, and Mexican hat plants showing root length increases of 66.7, 42.9, 35, and 33.3%, respectively. Biomass gains were consistent: Egyptian pea (29% fresh biomass, 33% dry), sesame (30% fresh, 39% dry), sorghum (36.6% total), and Mexican hat plant (31% fresh, 34% dry). Nutrient uptake surged systemically, including potassium (sesame: 42%, Egyptian pea: 17.8%), calcium (sesame: 54.5%, sorghum: 29.4%), and magnesium (Mexican hat plant: 32.4%, Egyptian pea: 22.5%). Physiologically, photosynthetic rates rose by 21.4-45% (highest in Egyptian pea), stomatal conductance improved by 23.3-71.4% (peak in sesame), and chlorophyll a and b levels increased by 30-39.1% and 44.4-150.8%, respectively, across species. These results suggested that F. mosseae could provide a sustainable, environment friendly substitute for chemical fertilizers, preparing for the future of agriculture, where ecological services such as crop productivity and soil fertility depend on mycorrhizas alongside conventional cultivation practices. Integrating AMF into agricultural systems offers a potential strategy for eco-friendly farming practices that are viable and secure for long-term food security and eco-sustainability.

Defect-enriched CuO/CeO2 nanostructure: in-depth structural characterization and photocatalytic performance

The catalytic activity of CeO2 can be modulated by incorporating defects and inducing strong metal-support interactions. Herein, we introduce CuO into CeO2 for generating oxygen vacancies (CeO2-x ) via the interaction between CuO and CeO2. The resultant catalyst CuO/CeO2 exhibited improved performance for the photocatalytic degradation of isoproturon (a herbicide). The improvement in catalytic performance was attributed to the oxygen vacancies and interfacial charge transfer between CuO and CeO2. Notably, the addition of CuO increased the oxygen vacancies in CeO2, correlating with the increase in the Ce3+ content (31.2%). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy studies substantiated the increase in surface oxygen vacancies in CeO2. We investigated the oxygen vacancies quantitatively and detected the chemical states of the Cu and Ce species. Photoluminescence (PL) studies validated the role of oxygen vacancies in restraining the recombination of photogenerated electron and hole pairs, thereby improving the catalytic activity of CuO/CeO2. Trapping experiments were conducted to identify the reactive species involved in the photocatalytic degradation process. Based on a thorough evaluation of the characteristics of the catalyst and photocatalysis experimental outcomes, a potential reaction mechanism was proposed. Furthermore, high-resolution mass spectrometry (HRMS) analysis was utilized to identify degradation intermediates, enabling us to outline the possible degradation pathways of isoproturon. Isoproturon (IPU) was effectively degraded under UV light with CuO/CeO2 compared with pristine CeO2. A 95% degradation efficiency was achieved with CuO/CeO2 (10 mg) for the IPU solution (10 μg L-1) within 120 minutes. This study provides detailed insights into the structural analysis of defective CeO2 and an in-depth mechanism of its photocatalysis, facilitating the design of high-performance ceria-based catalysts for photocatalytic degradation of emerging contaminants in water.

Pesticide dynamics and risk assessment in a plateau lake: Multiphase partitioning, drivers, and distribution in Southwestern China

Erhai Lake, a vital drinking water source for Dali, a highland agricultural city, faces potential contamination from pesticide residues, yet limited studies have assessed their distribution and impacts. This study investigates the occurrence, transport, partitioning, and ecological risks of pesticides in the lake's dissolved phase (DP), suspended particulate matter (SPM), and sediment (SD) samples collected from 22 sites across different seasons. The results showed significant temporal variations across different media, with spatial variations driven by crop-related patterns. Atrazine, etridiazole, and cis-permethrin were identified as the most abundant pesticides in DP, SPM, and SD, respectively. Notably, the source-sink dynamics were not only driven by deposition and resuspension but influenced by multiple sources and hydrodynamic processes such as precipitation, phytoplankton biomass, organic carbon, and winds. Ecotoxicological assessments indicated that permethrin, endrin, and endosulfan sulfate posed significant ecological risks to aquatic organisms. Although human health risks from pesticides were low, ongoing monitoring of atrazine is recommended due to its extensive use around Dali City.

Synergistic heterojunction effects in Ag3PO4/SnO2 nanocomposites: a photocatalytic study on isoproturon degradation

Introduction

Pesticides such as isoproturon are widely employed and represent a considerable environmental concern. The development of sustainable and efficient degrading techniques is crucial. Photocatalytic degradation employing semiconductor materials is a compelling solution. This study examines the synergistic advantages of heterojunction formation by synthesizing, characterizing, and improving the photocatalytic efficacy of Ag3PO4/SnO2 nanocomposites for the degradation of isoproturon.

Methods

The Ag3PO4/SnO2 nanocomposite was characterised using powder X-ray diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Ultraviolet-Diffuse Reflectance Spectroscopy (UV-DRS) and X-ray Photoelectron Spectroscopy (XPS). The effective synthesis of the Ag3PO4/SnO2 heterojunction was confirmed by characterization data from various techniques (PXRD, FTIR, SEM, UV-DRS, XPS).

Results and Discussion

Elemental mapping confirmed uniform distribution of O, P, Ag, and Sn. High-resolution mass spectrometry (HRMS) was employed to analyse degradation products. The Ag3PO4/SnO2 nanocomposite exhibited improved photocatalytic degradation of isoproturon compared to its precursors. In contrast to 25% for pure SnO2 and 41% for Ag3PO4, over 97% degradation was achieved using Ag3PO4/SnO2 nanocomposite within 120 min of light irradiation under identical conditions. The synergistic effects of heterojunction formation significantly enhanced isoproturon degradation using the Ag3PO4/SnO2 nanocomposite. The heterojunction reduces electron-hole recombination rate and enhances photogenerated charge carriers for degradation via effective charge separation. The improved photocatalytic activity is ascribed to the increased surface area of the nanocomposite. The analysis of HRMS data revealed the degradation products. The findings demonstrate the efficacy of Ag3PO4/SnO2 nanocomposites as photocatalysts for environmental remediation, namely in the breakdown of pesticides.

From Spear to Shield: A Novel Antifungal Drug that Safely Enhances Rice Immune Defenses

The infection and resistance of pathogenic fungi pose a significant threat to food crop safety, highlighting the urgent need for new green antifungal agents. Fusarium acid (FA) with its simple and novel structure correlates with the principles of green pesticides and has demonstrated substantial broad-spectrum antifungal activity. In a previous study, several promising lead compounds were identified. This study focused on further optimizing lead compound A1. Its inhibitory effect was evaluated against six different pathogenic fungi and several new promising compounds were identified. Notably, the anti-Magnaporthe oryzae (M. oryzae) activity of compound B4 was significantly enhanced with an EC50 value of 910 ng/mL. Rice safety tests indicated that B4 not only exhibited no adverse effect on rice growth and chlorophyll synthesis but also induced plant immunity by increasing the levels of polyphenol oxidase (PPO), peroxidase (POD), and superoxide dismutase (SOD), and soluble sugars. Further investigations into the antifungal mechanism of B4 indicated that it enhanced the permeability and damage of the mycelial membrane, thereby leading to electrolyte leakage and the loss of essential cellular substances. Subsequently, B4 induced the production of reactive oxygen species (ROS) in M. oryzae cell, including •OH, •O2-, and 1O2, while promoting increased levels of malondialdehyde (MDA) and SOD enzyme activity. Rice infection tests indicated that B4 effectively inhibited M. oryzae conidia activity and inhibited melanin production. These findings indicated that FA derivatives hold significant potential as a new strategy for M. oryzae disease management and offer valuable insights for the control of plant fungal diseases.

Coffee farmers willingness to accept payments for ecosystem services: Evidence from a choice experiment in Honduras

Coffee production in Central America provides a valuable yet volatile source of income for hundreds of thousands of small-scale farmers and employment for millions of workers. Expansion of coffee production into previously forested areas has caused the loss of a wide range of valuable ecosystem goods and services while contributing to global climate change and socioeconomic instability. Growth in carbon markets in agricultural settings and production of specialty coffees to meet consumer demands for products that support environmental and community outcomes suggests promise for favorable change. Yet, the incentives required to promote widespread transition toward sustainable coffee production are poorly understood, leaving policymakers with insufficient information to design scalable forest conservation initiatives. To fill this gap, we use a discrete choice experiment administered to coffee farmers in Honduras to understand farmers' willingness to conserve natural forest on farmlands in exchange for higher coffee prices and payments from carbon credits. Results suggest that payments for ecosystem services are a viable option for improving the sustainability of coffee production. However, coffee farmers may be reluctant to set aside significant percentages of the landscape for forest restoration. Low-income farmers appear more averse to forest conservation, suggesting the need for insurance against revenue losses.

Cyanobacteria-Pesticide Interactions and Their Implications for Sustainable Rice Agroecosystems

Modern agricultural practices rely heavily on fertilizers and pesticides to boost crop yields, essential for feeding the growing global population. However, their extensive use poses significant environmental risks. Chemical-based fertilizers and pesticides persist in ecosystems, potentially harming ecological stability. Wetland rice farming utilizing nitrogen-fixing cyanobacteria has emerged as an ecofriendly alternative, drawing attention due to its capacity to mitigate pesticide-related issues. Cyanobacteria, capable of fixing atmospheric nitrogen, thrive in low-nitrogen conditions and can aid plant growth. Some species can also biodegrade pesticides, offering a means to clean up contaminated environments. Researchers are exploring ways to leverage cyanobacteria's nitrogen fixation and biodegradation abilities for ecofriendly biofertilizers and environmental cleanup. This approach presents promise for sustainable agriculture and environmental preservation. The current study delves into multiple studies to investigate global pesticide usage levels, primary categorization, and persistence patterns. It also investigates cyanobacterial distribution and their interactions with pesticides in wetland rice ecosystems, aiming to enable their use in sustainable agriculture. Additionally, the review provides a thorough summary of the literature's findings about the potential of cyanobacteria in pesticide degradation.

Biodegradation of Organophosphorus Insecticides by Bacillus Species Isolated From Soil

This study investigates the biodegradation of methyl parathion, an organophosphate pesticide used in paddy fields. Microbial degradation transforms toxic pesticides into less harmful compounds, influenced by the microbial community in the soil. To isolate different microbial colonies, soil samples from an organophosphorus-treated groundnut field were plated on nutrient agar and MSM with 1% glucose and 0.25 mM methyl parathion. Biodegradation efficiency was determined by estimating the OP hydrolase enzyme activity spectrophotometrically. HPLC was used to quantify residual methyl parathion concentrations in the culture medium. The identified isolate effectively degraded methyl parathion in MSM with 0.25 mM methyl parathion which showed peak hydrolase activity (2.02 µmol/min/mg) after 96 h of incubation and the residual methyl parathion level was determined as 6.2 µmol by HPLC quantification. The efficient isolate was identified as Bacillus cereus by using a 16S rRNA molecular marker and the sequence was subjected to MEGA11 phylogenetic tree construction. The results show that the SM6 clade shared with B. cereus 16S rRNA sequence. B. cereus (SM6) showed substantial enzyme activity and the specific reported opdA gene-coded protein is involved in ATP hydrolysis. This OP hydrolase makes it a strong candidate for bioremediation of methyl parathion. Molecular analysis suggested that the opdA gene, likely chromosomally located, plays a key role in degradation, with potential involvement of the "Cell division protein FtsK" gene responsible for hydrolase activity. Organophosphorus compounds, widely used in agriculture, pose environmental concerns due to their persistence. This study focuses on isolating pesticide-degrading bacteria to expedite bioremediation, aiming for efficient degradation. This study highlights the cross-adaptation phenomenon, where B. cereus strains degrade similar compounds, improving bioremediation strategies.

Revealing microbial consortia that interfere with grapevine downy mildew through microbiome epidemiology

BACKGROUND

Plant and soil microbiomes can interfere with pathogen life cycles, but their influence on disease epidemiology remains understudied. Here, we analyzed the relationships between plant and soil microbiomes and long-term epidemiological records of grapevine downy mildew, a major disease caused by the oomycete Plasmopara viticola.

RESULTS

We found that certain microbial taxa were consistently more abundant in plots with lower disease incidence and severity and that the microbial community composition could predict disease incidence and severity. Microbial diversity was not strongly linked to epidemiological records, suggesting that disease incidence and severity is more related to the abundance of specific microbial taxa. These key taxa were identified in the topsoil, where the pathogen's oospores overwinter, and in the phyllosphere, where zoospores infect leaves. By contrast, the leaf endosphere, where the pathogen's mycelium develops, contained few taxa of interest. Surprisingly, the soil microbiota was a better predictor of disease incidence and severity than the leaf microbiota, suggesting that the soil microbiome could be a key indicator of the dynamics of this primarily aerial disease.

CONCLUSION

Our study integrates long-term epidemiological data with microbiome profiles of healthy plants to reveal fungi and bacteria relevant for the biocontrol of grapevine downy mildew. The resulting database provides a valuable resource for designing microbial consortia with potential biocontrol activity. The framework can be applied to other crop systems to guide the development of biocontrol strategies and reduce pesticide use in agriculture.

With or Without You?-A Critical Review on Pesticides in Food

Pesticides are very important in modern agriculture, protecting crops against pests and diseases to ensure food safety. However, the use of pesticides in food production has raised significant concerns regarding their potential impacts on human health and the environment. This review provides comprehensive insights into the current status, future projections, and debates surrounding pesticides in food. Beginning with a historical overview of pesticide use in agriculture, the types of pesticides commonly used and the presence of their residues in food commodities are explored. The health and environmental impacts associated with pesticide exposure are examined, including both human health effects and ecological consequences. An analysis of the regulatory frameworks governing pesticide management at international and national levels is presented, along with emerging trends and future projections in pesticide technologies and agricultural practices. Strategies for mitigating pesticide risks, such as Integrated Pest Management and alternative approaches to conventional pesticide use, are discussed. Finally, the controversies surrounding pesticide use, including public perception, consumer concerns, and policy debates, are addressed. Through a critical examination of these issues, this review underscores a growing need for innovative solutions that can effectively balance agricultural demands with human health and the environment, enabling more resilient and sustainable food production.

Combined Neurotoxic Effects of Commercial Formulations of Pyrethroid (Deltamethrin) and Neonicotinoid (Imidacloprid) Pesticides on Adult Zebrafish (Danio rerio): Behavioral, Molecular, and Histopathological Analysis

The use of different commercial products that involve one or multiple active substances with specific targeted-pests control has become a widespread practice. Because of this, a severe range of significant consequences has been often reported. Among the most used pesticides worldwide are deltamethrin (DM) and imidacloprid (IMI). With a significative effect on the insect's nervous system, DM acts on the voltage-gated sodium channels in nerve cell membranes, while IMI mimics the acetylcholine neurotransmitter by binding irreversibly to the nicotinic acetylcholine receptors. This study investigates the neurotoxic effects of sub-chronic exposure to commercial formulations of deltamethrin (DM) and imidacloprid (IMI) in adult zebrafish, both individually and in combination. The formulations used in this study contain additional ingredients commonly found in commercial pesticide products, which may contribute to overall toxicity. Fish were exposed to environmentally relevant concentrations of these pesticides for 21 days, individually or in combination. Behavioral, molecular, and histopathological analyses were conducted to assess the impact of these pesticides. Zebrafish exhibited dose-dependent behavioral alterations, particularly in the combined exposure groups, including increased erratic swimming and anxiety-like behavior. Gene expression analysis revealed significant changes in neurotrophic factors (BDNF, NGF, ntf-3, ntf-4/5, ntf-6/7) and their receptors (ntrk1, ntrk2a, ntrk2b, ntrk3a, ntrk3b, ngfra, ngfrb), indicating potential neurotoxic effects. Histopathological examination confirmed neuronal degeneration, gliosis, and vacuolization, with more severe impairments observed in pesticide mixture treatments. These findings highlight the neurotoxic potential of pesticide formulations in aquatic environments and emphasize the need for stricter regulations on pesticide mixtures and further research on pesticide interactions. Our findings emphasize that the combination of pesticides could trigger a synergistic effect by maximizing the toxicity of each compound. Thus, it is a well-known practice for pyrethroids and neonicotinoids to be used together in agriculture. Even so, its prevalence in agriculture and the need to investigate its actual impact on human health, biodiversity, and ecosystem mitigates the development of new strategies for assessing the risk and, at the same time, enhancing the effectiveness.

The Delineation of Management Zones of the Halyomorpha halys (Hemiptera: Pentatomidae) Population Based on Its Spatiotemporal Distribution for Precision Agriculture Purposes

Precision Agriculture is an agricultural management strategy that aims to increase farmers' profit, maximize crop productivity and sustainability, and protect the environment by applying inputs in optimum rates based on plant needs. The delineation of site-specific management zones is a crucial step at the application of Precision Agriculture. However, the procedure of delineating management zones for pest management is difficult since pest populations are dynamic and change spatially and temporally throughout a growing season. The objectives of this work is to study kiwi canopy characteristics, to correlate them with Halyomorpha halys (Hemiptera: Pentatomidae) populations and delineate management zones for pesticide applications in variable rates. To achieve this, four kiwi orchards in total were selected in the regions of Pieria and Imathia in Greece. Τen traps were installed from early May to late October within each selected kiwi orchard: two types of traps at every side of the orchards and the center. The installed traps were examined weekly, and the number of the captured H. halys was recorded. During the same days, sentinel satellite images were analyzed to calculate the indices: NDVI (Normalized Difference Vegetation Index) and NDWI (Normalized Difference Water Index). The collected data were combined in a GIS software to delineate management zones using a K means algorithm and unsupervised classification. The results of this three-year study showed population variability within the kiwi orchards since the population of H. halys was higher in field regions where NDVI and NDWI values were high. The delineation of management zones revealed that there are spatio-temporal stable zones in each field where there is high, medium, and low risk to develop H. halys populations. The benefits of the proposed strategy are multiple since it is expected that farmers will be able to reduce the production expenses of kiwifruits and environmental protection while increasing profit.

Highly sensitive and aptamer-based electrochemical fipronil biosensor based on primer exchange reaction and catalytic strand displacement dual recycling amplifications

BACKGROUND

The indiscriminate use of pesticides in agriculture has caused substantial harm to both the environment and human health. Therefore, it is crucial to develop methods for evaluating trace amounts of pesticide residues in food products. This study presents a highly sensitive electrochemical aptasensor to detect fipronil utilizing a new primer exchange reaction (PER)/catalytic strand displacement reaction (CSDR)-integrated dual signal amplification strategy.

RESULTS

Upon binding of fipronil to its specific aptamer in the template hairpin/aptamer complex probe, the template hairpin is released and hybridizes with primer to initiate PER for generating a substantial amount of assistant ssDNAs, which trigger subsequent CSDR for cyclically confining numerous methylene blue (MB)-conjugated signal probes onto sensing surface with existence of Klenow (exo-) fragment polymerase (KF) and deoxynucleotide triphosphates (dNTPs). Such many MB labels thus yield considerably enhanced electrochemical current signals, resulting in detection limit of 0.054 nM for fipronil within the dynamic range of 0.1 nM-1 μM. Moreover, the sensing method is highly selective and also effective for detecting low concentrations of fipronil in cabbage samples.

SIGNIFICANCE

With the successful demonstration of the significant signal amplification capability of our PER/CSDR methodology for fipronil, such electrochemical biosensor can be further developed as a robust sensing system for sensitive detection of various small molecules and other biomarkers by substituting the corresponding aptamers for different applications.

Scarcity of pesticide data in New Zealand with a focus on neonicotinoids: A review

Since Europe's 2018 neonicotinoid ban on outdoor use of clothianidin, imidacloprid, and thiamethoxam, there has been growing political, scientific, and public interest in further understanding the impact of neonicotinoids on bees and the environment. Here, we assessed the trends in pesticide use in New Zealand, with a particular focus on neonicotinoids, to aid discussion on their use and associated risks. Obtaining data on annual trends in pesticide quantities is challenging, as there is no central collection of pesticide data across the agrichemical or regulatory sectors in New Zealand. Consequently, the true scale and frequency of pesticide usage, including neonicotinoids, remain largely unknown. The difference in neonicotinoid use patterns between New Zealand, where 45 % of forage brassicas (annual planting) and pastures (infrequent planting) are grown from neonicotinoid-treated seeds, and northern hemisphere countries, where 56 % to over 90 % of annual food crops rely on neonicotinoid-treated seeds, indicates a lower overall neonicotinoid use in New Zealand. This difference underscores the need for region-specific approaches to pesticide management and regulation. Although residues can persist and migrate in the soil, current regulations only consider the risk of foliar spray to protect honey bees, overlooking the potential risks to native bees, which primarily live underground, as well as wider lethal and sublethal impacts of residues on non-target organisms. The lack of publicly accessible pesticide data limits scientific research on non-target and environmental effects, and the absence of readily available substitutes for neonicotinoids is the key challenge to be overcome in order to better manage the impact of these pesticides on New Zealand ecosystems.

Diamide insecticides in PM2.5: The unreported rural and urban air pollutants

The broad application of various pesticides guarantees the development of agriculture all over the word but has ultimately led to their ubiquitous release into the environment as hazardous chemical residues. Diamide insecticides (DAIs) are regarded as new choice for prevention and protection of agricultural crops and city landscaping plants from the pests in more and more countries. However, their presence in fine particulate matter (PM2.5) and associated health risks have not been studied. We reported for the first time the extensive distributions of PM2.5-bound DAIs in rural and urban areas of China, one of the world's largest agricultural countries. Eight DAIs were analyzed, and five were consistently detected in PM2.5 samples at concentrations primarily of pg m-3 level. Evident spatial/temporal variations were observed, with generally more serious DAIs' contamination and long-term health risks in rural areas during spring, summer and autumn. The first exploration of DAIs' toxicities on human bronchial epithelial cells discovered their capability of inhibiting cell viabilities, further demonstrating the potential detrimental effects of these emerging pollutants in PM2.5. This study confirms the widespread appearance of DAIs in PM2.5, emphasizing the need and urgency for concern about their pollution in both rural and urban air.

Applications and Challenges of Fluorescent Probes for the Detection of Pesticide Residues in Food

In food safety, detecting pesticide residues from environmental exposure is garnering increasing global attention. Therefore, it is crucial to develop rapid and straightforward detection methods for pesticide residues. In comparison to the limitations of traditional detection techniques, fluorescent probes have become ideal tools for detecting pesticide residues in food due to their superior non-destructive detecting and real-time monitoring capabilities. In this work, first, the types of pesticides commonly found in food and the fundamental principles underlying fluorescent probe materials are introduced. Second, the characteristics, applications, advantages, and limitations of prevalent fluorescent probes for food pesticide residue detection are evaluated. Finally, the significance of fluorescent probe materials in the detection of pesticide residues within the context of food safety and the developmental potential of fluorescent probes in this field are summarized and discussed, aiming to provide a valuable reference for developing new probes for pesticide residue detection and future research directions.

Uptake and translocation of pesticides in pepper and tomato plants

BACKGROUND

In this study, field and greenhouse experiments were done with spray application of the insecticides acetamiprid, indoxacarb, deltamethrin, λ-cyhalothrin, spinosad, chlorantraniliprole on pepper and tomato plants. Results were interpreted with numerical modeling.

RESULTS

Observed fruit concentration dynamics could be described overall well by modeling. After application, concentrations decreased in pepper and (slower) in tomato fruits (lower degradation and dissipation for tomato). Chemical input to individual above-ground compartments (fruit, leaf, stem, soil), arising from spray, was among the unknowns and hence estimated. Input to fruits was estimated 1-13% and 1-17% of the total applied amount; input to stem, leaf and/or soil 0-13% and 0-26% (pepper and tomato). Input showed high variation across compounds, with considerable uncertainty due to a partly low sensitivity of stem/leaf/soil input to fruit concentrations. The pathway stem-fruit was relevant for all compounds except λ-cyhalothrin (pepper, tomato) and deltamethrin (tomato). The pathways soil-root-stem-fruit and leaf-stem-fruit (phloem) were only sensitive for acetamiprid and chlorantraniliprole.

CONCLUSION

The dynamic model approach, implementing the appearance and growth of individual fruits, was after calibration successful in describing insecticide fate in pepper and tomato plants. Special consideration was given to dynamic modelling of plant growth and connected xylem and phloem flow. The dynamic approach was superior to assuming constant plant mass and transpiration, where growth dilution is described by rate constants. Information on the time-window of experiments within the vegetation period and on the number and appearance of individual fruits is important for adequately describing growth and thus chemical fate within plants. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Spray-induced gene silencing to control plant pathogenic fungi: A step-by-step guide

RNA interference (RNAi)-based control technologies are gaining popularity as potential alternatives to synthetic fungicides in the ongoing effort to manage plant pathogenic fungi. Among these methods, spray-induced gene silencing (SIGS) emerges as particularly promising due to its convenience and feasibility for development. This approach is a new technology for plant disease management, in which double-stranded RNAs (dsRNAs) targeting essential or virulence genes are applied to plants or plant products and subsequently absorbed by plant pathogens, triggering a gene silencing effect and the inhibition of the infection process. Spray-induced gene silencing has demonstrated efficacy in laboratory settings against various fungal pathogens. However, as research progressed from the laboratory to the greenhouse and field environments, novel challenges arose, such as ensuring the stability of dsRNAs and their effective delivery to fungal targets. Here, we provide a practical guide to SIGS for the control of plant pathogenic fungi. This guide outlines the essential steps and considerations needed for designing and assessing dsRNA molecules. It also addresses key challenges inherent to SIGS, including delivery and stability of dsRNA molecules, and how nanoencapsulation of dsRNAs can aid in overcoming these obstacles. Additionally, the guide underscores existing knowledge gaps that warrant further research and aims to provide assistance to researchers, especially those new to the field, encouraging the advancement of SIGS for the control of a broad range of fungal pathogens.

Oxidative DNA damage of lambda-cyhalothrin in model vertebrate organism

Pesticides, widely used for insect control in agriculture, public health, and veterinary medicine, are usually present as pollutants in aquatic environments. After contamination of water bodies, pesticides cause adverse effects on non-target organisms and long-term problems in the ecosystem. Lambda-cyhalothrin (LCH) is a chemical compound belonging to the family of synthetic pyrethroids (type II) and is an active ingredient in several insecticides. This study investigated the toxic effects (DNA damage) of LCH exposure on zebrafish for 24 and 72 h. After zebrafish (Danio rerio) were obtained commercially, acclimated, and adapted to laboratory conditions. They were randomly selected, transferred to the experimental aquariums (their average height is 2.51 ± 0.49 cm long, 10 L aquarium size of 10x20x35), and exposed to 0.1 mg/L LCH concentrations for 24 and 72 h. There was also a control and a solvent control group in the study, and whole body tissues of zebrafish were analyzed for 8-hydroxy-2-deoxyguanosine (8-OhdG) determination (ng/100 mg tissue), using an Agilent LC-MS/MS with electrospray ionization in positive ion mode. It was observed that the whole-body 8-OHdG tissue values were significantly increased in the group exposed to LCH for 72 h (9.82 ± 1.44) compared with the control group (6.60 ± 1.78, p = .004). These results suggest that LCH could lead to oxidative DNA damage by causing an increase in 8-OHdG activities in zebrafish, one of the aquatic ecosystem model organisms, indicating that it may also cause undesirable effects on other non-target species.

Multi-disciplinary investigation identifies increased potency of ethyl-parathion inhaled within a soil-dust matrix to cause acetylcholinesterase-dependent molecular impacts

Neurotoxicity investigations of inhaled organophosphorus pesticide (OP), ethyl-parathion (EP), were conducted in Sprague Dawley rats comparing exposures to EP volatilized at 0, 1, 10, and 20 mg/m3 versus EP incorporated into soil dust (5 mg/m3) at 0, 0.0095, 0.09, and 0.185 mg/mg3. All exposures were sublethal, caused no respiratory effects, and no effects on balance and coordination behavior. Both volatilized and dust-incorporated EP exposures significantly decreased acetylcholinesterase (AChE) activity in plasma and hippocampus tissue. Correspondingly, plasma and hippocampal dopamine levels spiked in these exposures suggesting compensatory cholinergic / dopaminergic signal balancing. The EP exposures significantly increased expression of pro-inflammatory genes, including MAPK-14, IL6, IL1β, and TNF-α, while global RNA-seq results identified significant enrichment of inflammation, oxidative stress, and apoptosis pathways. Remarkably, dust-incorporated EP impacted similar molecular endpoints as volatilized EP but at concentrations two orders of magnitude lower highlighting potentially increased potency of EP incorporated into soil dust.

Effects of atrazine, diuron and glyphosate mixtures on zebrafish embryos: acute toxicity and oxidative stress responses

Synthetic pesticides are known for their toxic effects on non-target aquatic organisms. However, little is known about their effects when present in mixtures, which are closer to realistic exposure scenarios. Therefore, this study evaluates the toxicity of pesticides such as diuron, atrazine and glyphosate, individually and in combination, in zebrafish embryos, investigating their mechanisms of oxidative stress. The results revealed acute toxicity for diuron and atrazine, with LC50 values of 9.6 mg/L and 53.57 mg/L for 96-h-old zebrafish, respectively. On the other hand, no effect was observed for glyphosate alone at the maximum concentration tested (100 mg/L). The mixture of diuron and atrazine showed a synergistic effect, resulting in a decrease in the LC50 of each pesticide. Mixtures of diuron + glyphosate and atrazine + glyphosate were considered additive and antagonistic, respectively. All biomarkers analyzed (AChE, LDH, GST, CAT and GPx) showed significant changes. Furthermore, an increase in ROS production was observed in larvae exposed to individual and in the mixture composed of atrazine and diuron. These findings indicate that atrazine and diuron exhibit increased toxicity when combined, with their mechanisms of action-both in isolation and in mixtures-being at least partially linked to oxidative stress.

Bioaccessibility of p,p'-DDT and p,p'-DDE in tropical soil ecosystems: a model based on pollutant speciation coefficients and the desorption free energy of adsorbed speciation forms

The bioaccessibility of organic pollutants in the environment depends on the nature and speciation of the contaminants and is determined using in vitro methods that simulate gastro-intestinal digestion. The objectives of the present study were to study the bioaccessibility coefficients of p,p'-DDT and p,p'-DDE in tropical soils based on the physico-chemical properties of the contaminant. The behavior of organic contaminants in soil ecosystems is characterized by their speciation and persistence, both of which depend on the extent to which the contaminant adsorbs to particulates in the soil matrix, as revealed in the characteristic persistence curve of the contaminant. Data are presented showing that the bioaccessibility coefficient of soil contaminants can be represented by a model based on the contaminant's speciation coefficients in the sample matrix, the desorption free energy of contaminant adsorbed speciation forms and temperature, provided its dissipation conforms to the multi-phase pseudo-zero order rate law. When the model was applied to determine the bio-accessibility coefficients of p,p'-DDT and p,p'-DDE in tropical soils based on previously published data from the literature, mean bioaccessibility coefficient values of 0.30 ± 0.21 (n = 8) and 0.35 ± 0.13 (n = 9) (p,p'-DDT), and 0.43 ± 0.05 (n = 4) and 0.20 ± 0.01 (n = 2) (p,p'-DDE), were obtained depending on whether determinations were carried out using chromatographic or radiotracer methods. The results fall within the range of literature values obtained using in vitro methods, thus attesting to the potential of the model presented for predicting the bioaccessibility coefficients of persistent organic pollutants in soil ecosystems.